Li-Fi: What is it and how does it work?

10th February 2019

As you might expect from their names, Wi-Fi and Li-Fi systems are similar. Essentially, they are both electromagnetic methods of transmitting data. The key difference between them is that Wi-Fi systems utilise radio waves to transfer information whereas Li-Fi uses visible light waves.

How does Li-Fi work?

Li-Fi is classed as a kind of visible light communications (VLC) system. What this means is that, within the system, it includes a photo-detector which receives the light signals and a signal processing element which takes those received signals and converts them into information readable by smart devices and computers etc.

The current fed to an LED bulb can be heightened and lowered at incredibly high speeds without being visible to the human eye. This is called being a semiconductor light source and as you’ll soon see, semiconductor light sources are imperative to a functional Li-Fi system.

Data is fed into the lightbulb; the bulb then dims and brightens at a rate we’re unable to see utilising signal processing technology. This data laden light beam is then read at a similarly high speed by the photo-detector (photodiode). The tiny, imperceptible changes in light are then converted into an electrical signal by the receiver this in turn is converted back to a binary stream of data, more recognisable as web video or audio, ready to use/view.

“Li-Fi has the potential to really shake things up in the world of connectivity. It might never fully replace Wi-Fi due to the limitations we’ve outlined above, but in terms of data transfer in and around an office environment, it could be incredibly impactful. If you’d like to discuss using cutting edge technologies to meet your organisations communications needs, get in contact with Challenger today!” – Jeff Eamens, Sales Director

What are the benefits of Li-Fi over Wi-Fi?

The primary advantage of Li-Fi over Wi-Fi is that it’s faster.

Li-Fi is said to be able to reach up to speeds of 224 gigabits per second which is considerably faster than Wi-Fi’s top speed. Despite this, Li-Fi has some specific complications which may prevent it totally replacing the use of Wi-Fi across the globe.

Li-Fi doesn’t just utilise a visible light source, it requires one. So, during the day you’ll need to constantly have your lights on if you want to stream online content or download something. Another complication caused by the use of light which is worth considering is that Li-Fi will not be able to transmit through walls, as such Wi-Fi systems may be preferable in certain circumstances (i.e offices etc.). Due to the requirement of overhead lighting to function, Li-Fi is unlikely to ever replace Wi-Fi in large, open spaces where electric lighting is unfeasible. However, in areas where radio signals do not transmit well or freely, Li-Fi could be the perfect solution to the connectivity problem.

The improved speeds of Li-Fi are likely to heavily impact the internet of things. With a higher speed of data transfer, more devices will be able to connect to each other much faster. Li-Fi’s shorter range works to its advantage in that it’s far more secure than traditional Wi-Fi and even reflected, the data embedded light beams could reach transfer rates of 70 megabits per second.

Will it catch on?

Time will tell. There are certainly enough advantages to Li-Fi that, in certain circumstances, it could be the ideal solution to long suffered problems. However, it’s unlikely that the rise of Li-Fi will see the end of Wi-Fi, in fact we expect to see the two systems working in tandem to shore up each other’s weaknesses.

Still struggling to work out what this could mean to your business, get in touch with us today on 0330 002 2111 or to see how we can help.